That has ever been the case. As soon as it works reliably, it's not "AI" any more. Take spellcheckers or collaborative filtering as examples, but there are lots more. Hofstadter in G.E.B. said it well:

> There is a related “Theorem” about progress in AI: once some mental function is programmed, people soon cease to consider it as an essential ingredient of “real thinking”. The ineluctable core of intelligence is always in that next thing which hasn’t yet been programmed. This “Theorem” was first proposed to me by Larry Tesler, so I call it Tesler’s Theorem: “AI is whatever hasn’t been done yet.”